clark



Oct. 15, 1929. F. s. CLARK WOOD DISTILLATION Filed April 19, 1927Inuehi'or:

fianklz'n LS: Clark L 1 M UWW ZZ Q- M N QNR awn/M52] W i g; I H. I I vi:a ate Illl/Ill Illl l I I I l l ll I Y Hnu F NN;nHHUHHHHHNHHHHH HHHHHMHIm em m Patented Oct. 15, 1929 UNITED STATES PATENT OFFICE FRANKLIN S.CLARK, OF PALM BEACH, FLORIDA; L. YANCEY CLARK AND FRANKLIN S. CLARK,JR., EXECUTORS OF SAID FRANKLIN S. CLARK, DECEASED WOOD DISTILLATIONApplication filed April 19,

My present invention relates to a method for distilling wood, for theeflicient production of natural cducts and distillation products.

One of the principal objects of this inven-. tion is the regulation ofthe heat between certain ranges, for certain periods so that cleanfractions may be secured without contamination from following oradjacent fractions.

This includes a separation of natural educts' from the products ofdestructive distillation. Another important object of the invention isthe efiicient operation of an oven for distillation of woods which willbe carried on at low cost, which will result in a minimum wear and tearon equipment, and which sepure the maximum yield of desirable distilate.I

Other objects and advantages will appear as the description proceeds.

To this end the invention contemplates the use of a still substantiallyrectangular in cross section and of an elongated form which may be firedfrom each end. The oven proper may be constructed of sheet iron,provided at the top and bottom withoutlets for distillation products,and in between with a track upon which may be run the cars containingthe wood to be treated. I propose to make the tracks at substantiallythe ground level, so that no unnecessary equipment such as cranes or thelike will be needed to charge or empty the retort.

The oven or retort itself is surrounded with flues for heating the sameinitially with a free fire from wood, coal, coke, gas, oil or the like,which fire, however, is not suflicient to cause distillation. This firstand free fire is merely to initially heat the still or retort, toprevent condensation. The distillation temperature is reached by meansof pressure steam contained in pipes hung from the car tracks or on theside walls. Sulficient open, free or unconfined steam is introduced intothe bottom of the still to keep the distillation products moving throughthe apparatus. When the process is about complete, a certain amount ofsuperheated steamsis let into the retortto finally drive out anyremaining desirable products from the charcoal.

1927. Serial No. 184,937.

Suitable condensers, purifiers and other devices are provided inconnection with the still or retort above mentioned to insure anefficient collection of products.

It is to be understood, that a very important feature of the inventionis the initial heating of the retort with free fire, the maintaining ofthe distillation range with controlled pressure steam, the provision ofslight How of open or free steam to keep the products moving, and thefinal clean out with superheated steam. Y

The invention further consists in the com bination, construction, andarrangement of parts and the various steps set out in detail in thespecification andshown in the drawings.

In the drawings v Fig. 1 is a view partly in section of a device forcarrying out my invention.

Fig. 2 is a longitudinal sectional view through the device.

Referring now with particularity to the embodiment illustrated, I haveshown at l a sheet metal still or retort, elongated to take a series ofwood carrying cars. The ground level is indicatedat 2.

Built up aroundthe still, I provide brick work 3 or the like having aseries of fines 4 therein. The still is adapted to be heated by freefires built at each end thereof, the heat travelling circuitouslytoward'the center of the retort, upwardly, back to the fire region andthen to the stack. In this manner the entire side walls are thoroughlyheated while at the same time the'top and bottom are maintainedrelatively cool.

Mounted upon supports 5, I provide tracks 6 to receive the wood carryingtrucks 7. As these tracks 6 are at ground level, the loading andunloading of the retort may be expeditiously carried out with theminimum amount of effort.

A series of steam pipes 8 is provided, hung from the track supports andsubstantially cover the longitudinal area of the retort. The pipes 8 areconnected to a suitable source of steam under pressure, controlled byvalve 9. By this system, the temperature within the retort may beabsolutely maintained between admitting superheated steam through thepipe 13 controlled by valve 14, this last part of the products may bedriven over.

The bottom 15 of the retort is preferably dished to permit the rosinmelted out during the first part of the treatment, and the tar producedduring the later part of the treatment to collect, and pass out throughthe pipe 16. This pipe has a low outlet 17 and an upper outlet 18. Whenvalve'19 is open, the first product, namely, rosin passes out throughthe outlet 17. When upon increasing the temperature, tar is produced,the valve 19 is closed and the tar exits through the pipe 18 to asuitable container.

The roof 20 of the retort is likewise curved, and provision is made fora thermometer 21 therein. A take-off or gooseneck 22 is connected to adowncomer 23 which is provided with suitable valves 24 and 25respectively,

and an air condenser 26. From the upper part of these air condensercoils, the products are conducted to a purifier 27 consisting of a tankprovided with baffle plates 29. The tank is partially filled with analkali such as caustic soda and the gaseous products are made to bubblethrough the caustic to removeany of the ligneous acids. After passingthe purifier, the gases may be passed through the condenser 30 and thecondensate collected.

The operation of the systemis substantially as\f7\c;llows.

hile this treatment is particularly adapted for the distillation andtreatment of soft woods such as pine, and for the collection of theparticular products of the soft woods, yet obviously other woods may besimilarly treated efficiently. I will describe, however, the

. treatment of a batch of pine wood.

The cars 7 are loaded with wood to be treated, cut preferably intopieces of convenient length having no cross sectional measurementgreater than four inches. This size has been found sufiiciently small topermit complete heatpenetra'tion without undue raise of temperature. Anynumber of cars may be utilized consistent with the length of the retort.

Fires are now built at each end of the retort to initially heat thesame, although these .fires should be of such a character that adestructive distillation temperature cannot be reached with them alone.Suchwood fires may be advantageously used to cheaply raise thetemperature to prevent condensation on the retort walls during the firststages.

As the temperature rises, pressure steam is introduced into the pipes 8,being fed from a boiler operating under substantially 200 lbs pressure.During the first fifteen hours of treatment, the temperature should beslowly raised and kept below 270 to 280 F. At this point destructivedistillation begins, and one of the principal objects is to prevent a m1X.- ture of the natural educts and the destruct1. e distillationproducts. If the temperature 1s not increased beyond this point,practlcally all of the rosin will melt and be collected through theoutlet 17 the valve 19 bemg open, and a very good quality of turpentineWlll be produced. Throughout this period a sufficient quantity of openor free steam 1s admitted throughihe pipe 10 to keepthe educts moving.

The vaporous educts not condensed by the air condenser pass upwardly,through the purifier, and then are eventually condensed at 30 andcollected.

After this first period has been completed, with the controlled steam,and practically all of the natural educts clearly fractionated, thesteam is turned off and destructive distillation begun by firing thefree fires at the ends of the retorts.

When this later period begins, the valve 25 should be closed and valve24 opened in order to permit the heavy oils to be condensed in thecondenser 32 and not pass upwardly and contaminate the condenser 26 andbeyond. At the same time, the valve 19 should beclosed astar will now beproduced and pass out ofthe tar outlet 18. The separate condenser 32 isused to condense such of the distillate as now comes over.

After some hours of such treatment, the wood will be exhausted and onlycharcoal remains. Any remnants of desirable products contained in thiswood may be forced out by introducing superheated steam through the pipe13. As the charcoal at this stage is at a relatively high temperaturethe superheated steam will have no detrimental effect on it,

but will remove the last traces of distillate.

Upon cooling, the end doors or gates of the retort may be opened and thecars containing spent charcoal removed.

From the above operation, it will be noted that the equipment is onlysubjected to a high temperature for ashort period of time so thatexcessive wear and tear is avoided.

Due to the fact that during the first or natural educt period, thetemperature is absolutely controlled, and there is no contamination ofthe distilled vapors by products of destructive distillation, a cleanand efficient fractionis obtained,both as to distillate and melted outmaterials.

What is claimed is: v

A method of operating a wood distilling device which consists of aretort surrounded by a heating chamber, a furnace to heat such chamber,and having closed and open steam pipes within it, which comprisesheating said retort first by fire within the furnace to a temperaturewhich will prevent condensation of water or other vapors upon its Walls,then heating it to a temperature which will remove volatile substancesexisting in the Wood Without changing their chemical composition, thenheating it by fire to a destructive dlstlllfltion temperature andmaintainlng said heat until the wood is carbonized, free steam beingpassed into the retort throughout the last two heating periods insufiicient quantity to convey away the vapors produced.

In testimony whereof, I affix my signature.

FRANKLIN S. CLARK.

